Do you need an amp to use these? I read some reviews saying an amp was needed but they were pretty old, not sure if that still applies to new smartphones
FoxmccoxThese will require an amp even for your smartphone, they do make solid state battery operated amps that will power these just fine. Look around on ebay got one for around $20.00 w/ L-ion battery , nothing fancy however it does what it's supposed to do
FoxmccoxJust to answer your question, I pulled out my HD650s and plugged them into my S7. The S7 at max volume is louder than I'd need them, but only by one level. It'd be fine for relaxing at home, but these aren't the type of headphones you take on a bus or plane. Using my IE80s I'm only at 30-40% volume in the same environment for the same volume. So they're definitely harder to drive.
J.CleverlyThough would you really take $250, limited edition, open backed headphones and wear them in a noisy, busy situation? If that's the level of money you can risk, a $100 amp probably isn't a concern.
poseidon0025I'm wearing one right now, sitting in a library with noisy kids running wildly around kicking chairs, pulling other people's hair/s out, and 10 meters away someone is on the phone speaking loudly in a language other than English. I am using my encore mDSD dac which is just under the $100 mark.